The invention relates to a steering device using gas jets which create thrust forces in directions determined by guidance commands; it also relates to a missile equipped with such a device.
A gas jet steering device intended more specifically for modifying the flight path of a projectile or missile comprises a set of fixed nozzles disposed in a ring at the periphery of the body of the missile and a primary energy source which generates a gas flow, generally with a continuous delivery rate. Between the inlets of the nozzles for exhausting the gas flow and the outlet of the gas source, there are disposed means for switching the gas flow into one or simultaneously into several nozzles in keeping with the guidance commands available on board the missile. Furthermore, in some applications, it is desirable to have available simultaneously a longitudinal thrust force for maintaining the cruising speed of the missile and a transverse force for modifying the flight direction of this missile.
It is known, more especially from French patent No. 77 10755, filed on Apr. 8th, 1977 in the name of the Applicant, to construct a gas jet steering device in which distribution or switching means are provided for directing the gas flow towards given exhaust nozzles. In a first embodiment described, corresponding to a single steering plane, the device comprises two fixed diametrically opposite nozzles; the distribution means is formed by a mobile vane disposed in the divergent conduits for supplying the nozzles with gas flow; this mobile vane is hinged about an axis perpendicular to the plane containing the nozzles and is actuated by a pneumatic jack so as to swivel alternately towards one nozzle or the other. In a second embodiment described in this patent, the steering device comprises a set of four fixed nozzles diametrically opposite in pairs, each of the pairs of nozzles being situated in the two orthogonal steering planes; the means for distributing the gas flow is a four branch vane hinged to a central swivel joint and disposed in the divergent conduits for supplying the nozzles with gas flow, so that two adjacent nozzles are simultaneously open whereas the other two nozzles remain closed.
The steering device of the invention relates more particularly to this second embodiment of the prior art which presents the following drawbacks: firstly, the transverse thrust force results from the geometrical sum of two orthogonal elementary forces resulting in a weight penalty on the gas flow generator and secondly manufacture of the four-branch vane hinged to a swivel joint raises technological difficulties.
The aim of the invention is to eliminate the above-mentioned drawbacks which are inherent in the gas jet steering devices of the prior art.